are you using MIL-HDBK-217F or MIL-217Plus??
If you are using MIL-HDBK-217F you need not worry about quality factors. Because The MIL-217F is not updated from 1995 and it is abonded. More over for Military components the quality factor will be given in Datasheets. for other components like Commercial, automative and COTS parts i use to take MIL-SPEC Quality factor which is the value is 3. We should not take Commercial value 10 in prediction. Because there are lot of changes in capacitors models, size and other specs compare to 1995. Directly you can use MIL-SPEC for other then milatary componenets.
Coming to the 217Plus, 217plus is new standard. now a days most of the people are using 217plus for prediction. because it is depend on manufacterer specs, process grade and hope it gives acurate value.
I think its useful.